Laminate structures, such as printed circuit boards, are prepared by first laminating a sub-composite structure with exterior sheets/layers and/or other sub-composite structures. One or more holes may be formed (e.g. drilled) through the sub-composite for buried via holes. This may be followed by depositing plating resist within the one or more holes using a via hole filling machine such as screen printing or a vertical squeeze vacuum via fill. Despite using a via fill machine, the deposition of the plating resist leaves an excess (or residual) plating resist on upper and/or lower surfaces of the sub-composite structure. Once the plating resist has been cured, the excess plating resist needs to be removed from the upper and lower surfaces of the sub-composite structure in order to provide a substantially flat and/or clean upper and/or lower surfaces. However, there currently does not exist a machine that can scrub a thin laminate (e.g., >6 mil limiting panel size by very expensive tight control required tool, >20 mil for standard tool). Manual/hand scrubbing the upper and lower surfaces of the sub-composite structure not only may result in inconsistent surfaces on sub-composite structures (e.g., inconsistent cleaning, varying thicknesses, etc.) but would also be very expensive to implement.
Consequently, what is needed a way to remove excess via fill material, such as plating resist, during the formation of a plated through-hole that is consistent from structure to structure and is time as well as cost effective.